Identification of very-low transverse momentum muons with the ATLAS experiment

The standard muon identification in ATLAS experiment is optimized for muons with transverse momentum (pT) above 5 GeV. However searches for low mass resonances and many B physics studies often need to identify muons with lower pT, where standard algorithms suffer from large backgrounds originating from sources such as hadrons decay in flight. A new "Low-pT" identification has been developed to allow optimal muon identification down to 3 GeV in pT using variables that are sensitive to track kinks in the inner detector and to the imbalance of momentum measured in the inner detector and in the muon spectrometer (MS). The new "Low-pT" identification, analyzed in simulation and in data, shows good efficiencies for muons produced in hard collisions and is effective in rejecting backgrounds